We have generated a monoclonal directed against the alpha chain of the human FcepsilonRI. With this reagent we found that FcepsilonRI is expressed on the surface of Langerhans cells in human skin and we are attempting to determine the possible role of this receptor in atopic dermatitis. We are also looking actively at the possibility that FcepsilonRI might be expressed in other cells such as eosinophils, macrophages, NK cells etc...